Thanks Judi for your question! I’m sorry to hear that Bella had a tough start to life but it sounds like she is in better hands!
Anxiety is a growing problem and it’s something i see more frequently in dogs with a tougher start to life! I would recommend having a board certified animal behaviorist come and work with you and Bella! A boarded animal behaviorist is someone who went through veterinary school like me but did an additional 4 years specifically for animal behavior issues.
Here is a link to check out !
https://www.dacvb.org/search/custom.asp?id=4709
You can also talk to your vet about anxiety medication but these are most effective when used in combination with behavioral modification with a behaviorist!